Germany's top domestic security minister yesterday called the al Qaeda threat "really dangerous," as the FBI prepared to tell Congress that the terrorist network remained a viable threat to again attack U.S. targets in this country and abroad."The strength of al Qaeda groups is as high as it was before September 11 … maybe also a little bit more than before," German Interior Minister Otto Schily told reporters in Washington, where he visited with Attorney General John Ashcroft and Homeland Security Secretary Tom Ridge."The threat has dimensions which are really dangerous," Mr. Schily said, adding that a war by the United States on Iraq would inflame Muslim extremists."If a war takes place, the emotions will intensify," he said. "It's a matter of concern. You can't exclude repercussions."The long-awaited FBI report, part of a written assessment of potential terrorist threats facing the United States, is expected to be delivered next week in closed session to the Senate and House intelligence committees.The classified report concludes that al Qaeda "remains, for the foreseeable future, the most serious threat against the United States," say law enforcement authorities and other sources. The report comes as Muslims prepare to make their annual pilgrimage to Mecca during a three-day holy period beginning Sunday known as the Hajj.The assessment, law enforcement sources say, is based on information obtained by the FBI and others from captured al Qaeda documents, interviews with detained terrorists and other sources.Known as the "National Threat Assessment," it describes the potential for new attacks against U.S. targets including the use of chemical and biological weapons as heightened by pending U.S. military action in Iraq, which the Bush administration considers an ally of the al Qaeda network, law enforcement sources said.The al Qaeda network has not conducted a major terrorist attack since last year. Several top al Qaeda leaders, including terrorist mastermind Osama bin Laden, Ayman Al-Zawahiri and Khalid Shaikh Mohammed, remain at large. They were key figures in the September 11 attacks that killed more than 3,000 people.Thousands of al Qaeda and Taliban guerrillas disappeared from Afghanistan after the Taliban regime collapsed in November 2001. They abandoned several training camps, which yielded significant intelligence data about al Qaeda's leadership and its activities.Since the September 11 attacks on the World Trade Center and the Pentagon, more than 3,000 al Qaeda suspects and associates have been captured in more than 100 countries. Nearly a third of the organization's leadership has either been killed or captured.But federal authorities, including the FBI, remain concerned that the al Qaeda organization has established "sleeper cells" in the United States and elsewhere, which like the 19 hijackers who commandeered four jetliners on September 11 could strike against U.S. targets on their own, the sources say.Last month, Canadian authorities confirmed that the terrorist network had established sleeper cells in Canada whose members had the "capability and conviction" to support terrorist activities all across North America. The Canadian Security and Intelligence Service described the cells as secretive, operational and loyal to bin Laden.The FBI assessment, the first of its kind, had been requested by Congress in 1999 to determine the potential of terrorist threats against U.S. targets involving chemical and biological materials or with other weapons of mass destruction.The FBI developed a threat assessment draft in 2001 that described terrorist groups and state sponsors but did not assess the threat of an attack on the United States. The draft also omitted any assessments of the training, skill levels, resources, sophistication, specific capabilities, intent, likelihood of attack and potential targets of terrorists, and did not include information on methods they might use.The draft, criticized by both Republicans and Democrats, also contained no analysis of terrorists' attempts to obtain chemical, biological, radiological or nuclear weapons.The FBI has long believed that the al Qaeda organization has maintained offices throughout the Middle East, Europe, Canada and the United States. The FBI recently said bin Laden's group had aligned itself with other international terrorists, with whom the network was attempting to manipulate Islamic extremists in order to attack U.S. targets at home and abroad.